If Mark Twain were to characterize the legislative veto two years after the U.S. Supreme Court called it "dead," he would probably say that reports of its demise have been greatly exaggerated.

The court in 1983 handed down one of the broadest decisions in its history, sounding what Justice Byron R. White called "the death knell" for about 200 laws containing provisions for Congress to veto action taken by executive departments and agencies.

Commentators at the time observed that by declaring the legislative veto unconstitutional and calling into question more laws in one decision than it had struck down in its entire history, the court had drastically altered the balance of power, removing authority from Congress and delivering it into the hands of the White House.

But a study done earlier this year by the Congressional Research Service declares that the legislative veto "is alive and well."

Sources on Capitol Hill and in federal agencies report that Congress has found numerous ways of accomplishing the same thing as a legislative veto, and has been as active as ever in overseeing executive branch activities.

And, despite the court's decision disapproving of the use of the veto in the case Immigration and Naturalization Service v. Chadha, Congress has since enacted more than 50 legislative-veto provisions in scores of laws.

The latest legislative veto was passed July 26 by the Senate as an amendment to legislation on the budgets of the Federal Trade Commission and the Consumer Product Safety Commission.

The legislative veto was first used in the 1930s to reconcile two conflicting needs, according to the forthcoming book "Constitutional Conflicts Between Congress and the President" by political scientist Louis Fisher.

As the federal government grew, executive officials wanted more authority, while Congress insisted on controlling the agencies and departments without constantly passing new laws.

The initial legislative veto allowed the president, agencies and departments to propose rules and regulations that would become law unless vetoed by the House or Senate, or in some cases both. Soon, the procedure evolved into a mechanism that in some instances required congressional approval instead of disapproval, and permitted certain congressional committees to challenge executive actions.

A congressional veto exists in a wide variety of laws touching on almost every aspect of governance.

The authority for the legislature to veto an executive decision exists in laws on the budget, federal reorganization, foreign affairs, war powers, and such regulatory areas as trade, safety, energy, the environment and the economy.

Of the approximately 400 legislative-veto provisions enacted since 1932, at least two-thirds were passed after 1970.

Eighty-seven legislative-veto provisions were enacted in 1974-75, suggesting to some observers the heightened congressional oversight that resulted from Watergate.

But despite the broad authority to exercise vetoes that Congress possessed before Chadha, it was rarely used.

Before the court's decision, Congress passed 226 out of 1,180 proposed veto resolutions, only 19 of which had nullified a rule promulgated by an agency.

Although the precise issue in Chadha concerned the constitutionality of the one-chamber veto, the scope of the decision seemed much broader.

In a concurring opinion, Justice Lewis F. Powell Jr. observed that the decision "apparently will invalidate every use of the legislative veto."

That observation, as well as White's remark that the decision sounded a death knell for 200 laws with veto provisions, went unchallenged by the court's opinion, suggesting the court's disapproval of all uses of the legislative veto.

Congress, however, has found "ingenious and novel" methods of checking the power of the executive, according to Fisher.

"Some of the new legislative vetoes are informal and nonstatutory," Fisher writes. "A few rely on convoluted uses of the rulemaking powers available to the House and the Senate. Others are indistinguishable from the legislative veto supposedly struck down by the court."

That view was supported by sources on Capitol Hill. As one congressional aide put it:

"Congress can be a very creative animal. When you slap it down, a hundred new powers, like flowers, will bloom."

For example, a key provision in the Impoundment Control Act of 1974, considered in doubt after Chadha, permits the president, acting in conjunction with the legislature, to delay or halt funding for a federal program or agency.

The provision, known as a deferral, gives either chamber of Congress the power to disapprove of the delay by adopting a simple resolution.

But then-Office of Management and Budget Director David A. Stockman told ranking congressmen in the budget committees that they should place their objections to deferrals in appropriations bills, which the president would sign if he had no other disagreements with the bills, according to an OMB spokesman.

The congressional objections "almost always go through," said the spokesman, Edwin L. Dale Jr.

He added that the administration "has been grappling with the legislative veto ever since the 1983 Supreme Court decision."

Dale said the Reagan administration tells agencies to ignore actual legislative-veto provisions that have been passed since the court's decision, and some legislators have begun a drive to reintroduce a veto that they think can pass constitutional muster.

A bipartisan group of 10 senators, ranging politically from Michigan Democrat Carl M. Levin to South Carolina Republican Strom Thurmond, have introduced legislation to restore the legislative veto.

The bill, now in committee, is the latest in a line of dozens of proposals that have been submitted to Congress since 1983.

Under the proposal, co-sponsored by Levin and Charles E. Grassley (R-Iowa), both chambers together would be able to cut off funds to an agency that passes regulations disapproved by Congress.

The administration has opposed the bill, saying parts of it are as unconstitutional as the veto in the Chadha case.

In testimony last month before the Senate Judiciary subcommittee on administrative practice and procedure, Acting Assistant Attorney General James M. Spears also said the bill might introduce "massive delay, uncertainty and paper work into the administrative process."

Another proposal, introduced in the House by Rep. Trent Lott (R-Miss.) and 73 co-sponsors, would adopt a legislative veto that would require the president to approve congressional attempts to halt an executive decision.

Even if any of the bills pass, according to some observers, the power of the legislative veto may lie more in its availability than in its actual use.

Stuart E. Eizenstat, the chief domestic policy adviser to President Jimmy Carter, said in an interview that history has demonstrated that the effectiveness of the legislative veto lies mainly in the threat of using it.

"It was used as a threat, which could be relied upon to persuade an agency to withdraw or modify a proposed rule to satisfy a committee or congressman," he said.